EXHIBIT 5.1

                                    HALE AND DORR
                                   60 STATE STREET
                                  BOSTON, MA  02109

                                    April 12, 1996

Eastern Bancorp, Inc.
537 Central Avenue
Dover, MA  03820

    Re:       1987 STOCK OPTION PLAN

Ladies and Gentlemen:

    We have assisted in the preparation of a Registration Statement on Form S-8
(the "Registration Statement") to be filed with the Securities and Exchange
Commission relating to 80,000 shares of Common Stock, $.01 par value per share
(the "Shares"), of Eastern Bancorp, Inc., a Delaware corporation (the
"Company"), issuable under the Company's 1987 Stock Option Plan (the "Plan").

    We have examined the Restated Certificate of Incorporation of the Company
and the By-Laws of the Company, each as amended to date, and originals, or
copies certified to our satisfaction, of all pertinent records of the meetings
of the directors and stockholders of the Company, the Registration Statement and
such other documents relating to the Company as we have deemed material for the
purposes of this opinion.

    In examination of the foregoing documents, we have assumed the genuineness
of all signatures and the authenticity of all documents submitted to us as
originals, the conformity to original documents of all documents submitted to us
as certified or photostatic copies, and the authenticity of the originals of
such latter documents.

    Based on the foregoing, we are of the opinion that the Company has duly
authorized for issuance the shares of its Common Stock covered by the
Registration Statement to be issued under the Plan, as described in the
Registration Statement, and such shares, when issued in accordance with the
terms of the Plan, will be legally issued, fully paid and nonassessable.



    We hereby consent to the filing of this opinion with the Securities and
Exchange Commission in connection with the Registration Statement.


                                                 Very truly yours,

                                                 /s/ Hale and Dorr

                                                 HALE AND DORR